Paging system that allows caller/subscriber interconnection

ABSTRACT

A telecommunications system that performs page-connect paging is disclosed. The telecommunications system of this invention includes a paging system (28) that is designed to receive calls from page-connect paging system subscribers. Once such a call is received, the system (28) parks the call on hold while sending a page to the subscriber. The subscriber can then call the paging terminal (28) to automatically be connected with the calling party. The system further includes a cordless telephone-2 system (26) wherein each of the system subscribers is further provided with a portable handset (26) from which he can access the publicly switched telephone network. Subscribers with the handset, upon receiving a page-connect page, can automatically dial the paging terminal (28) to be connected to their calling parties. Thus, the telecommunications system of this invention provides a convenient means of providing subscribers with portable telephone service that allows them to both make outgoing calls and receive incoming calls.

This application is a continuation-in-part of U.S. patent applicationSer. No. 07/848,413 filed Mar. 6, 1992, now issued as U.S. Pat. No.5,307,399.

FIELD OF THE INVENTION

This invention relates generally to telecommunications systems and, moreparticularly, to a paging system that will automatically connect asystem subscriber to a person calling the subscriber.

BACKGROUND OF THE INVENTION

A paging system is used to send electronic notices, called pages, tosystem subscribers to inform them that they have been called by otherindividuals. A typical paging system includes a paging terminal and oneor more paging stations. The paging terminal is connected to thepublicly switched telephone network and is configured to receiveincoming telephone calls from individuals interested in accessing thesystem subscribers. In response to receiving a call, the paging terminalcreates a block of information, a page, for the subscriber. The page isforwarded to the paging stations, which then broadcast the page. Systemsubscribers carry pagers, which are miniaturized radio receivers. When apager receives a page for the subscriber to whom the pager has beenassigned, the pager actuates an internal audio annunciator and/ordisplay to reform the subscriber of the page and its contents.

A paging system is typically configured so that a system subscriber canselect the class or type of paging service that he wants to receive. Thebasic service many paging systems offer is to simply broadcast a page tothe subscriber to inform the subscriber that he has been called. Oncethe subscriber has received this page, which is indicated by a beepingtone and/or a flashing light, the subscriber must access the pagingterminal to find the identity, or at least the phone number, of thecalling party. Many paging systems offer subscribers an intermediatelevel of service, which allows the subscribers to receive a shortnumeric or alphanumeric message as part of the page. This message ispresented on a small display integral with the pager. Some pagingsystems offer an even more advanced level of service that allows acaller to leave a message that will be transmitted to the subscriber. Apager carried by a subscriber using this service includes a small audiosignal-processing circuit that, upon receipt of the page, plays themessage on a small speaker also integral with the pager. Many pagingsystems also include some type of voice-mail storage capability thatallows a caller to record a message that the subscriber can retrieve athis convenience. Some paging systems are even configured to allow systemsubscribers to make customized greetings that instruct callers how tomake a page and/or leave a voice-mail message. Many paging systems areconfigured to allow a subscriber to select the particular services thatform his/her package of paging services.

While paging systems have proved a useful means for contactingindividuals who are away from their telephones, they suffer a seriouslimitation. Few paging systems offer any means for actually connecting asubscriber to a caller. Consequently, many individuals prefer tosubscribe to cellular telephone systems. These systems providesubscribers with cordless portable telephones. These systems alsoinclude a number of fixed mobile telephone switching offices (MTSOs).Equipment in the MTSOs tracks the cellular telephones and provides aradio link between the callers and cellular telephone subscribers. Adisadvantage of cellular telephone systems, however, is that there arelimited radio frequencies over which cellular service can be offered.Consequently, cellular telephone systems can be used to offercommunications services for only a limited number of subscribers.Another disadvantage of cellular telephone systems is that, in order fora subscriber to use the his portable telephone, he must be in an areathat is served by his cellular service provider. Many cellular providersoffer service through only a limited service area. Once a subscriberleaves the service area, he is no longer able to receive incoming calls.

SUMMARY OF THE INVENTION

This invention relates generally to a telecommunications system thatprovides portable communication connections to a large number ofindividuals over a large geographic area and that can provide suchservice at minimal expense. More particularly, this invention is relatedto a paging system intended to be used in conjunction with a cordlesstelephone-2 (CT-2) communications system.

The telecommunications system of this invention includes a paging systemthat includes caller/subscriber interconnect or "page-connect"capabilities. In one preferred embodiment of this invention, the pagingsystem includes a paging terminal that is configured so that eachpage-connect service subscriber is assigned two telephone numbers. Onetelephone number, the public telephone number, is the number thesubscriber distributes as his/her pager number. The second telephonenumber is the subscriber's private telephone number; the subscriberkeeps this number confidential. The paging terminal of this inventionalso includes a switch that can selectively establish an interconnectionbetween a call to the subscriber's public number and a call to his/hercomplementary private number.

When a caller dials the public number of a subscriber to this system,the paging terminal initially places the call on hold and simultaneouslybroadcasts a page to the subscriber. The subscriber then has apredetermined amount of time to call the system over his private number.If the subscriber calls in during this time, the paging terminal willautomatically interconnect the caller and the subscriber so that the twoparties can converse in a normal manner.

The paging system of this invention is designed to be used inconjunction with a cordless telephone-2 (CT-2) system to provide alow-cost portable bi-directional communications system. In a CT-2system, the subscribers are provided with small, low-powered portableradio transceivers called handsets. The system also includes a set ofbase stations that are located throughout the geographic area in whichthe system is installed. The base stations are connected to the publiclyswitched telephone network. A CT-2 system subscriber makes a telephonecall by first establishing a radio link through his/her handset to anearby base station. The subscriber then transmits the number of theparty being called; equipment in the base station then establishes thesubscriber/called party interconnection over the publicly switchedtelephone network.

The paging system of this invention, when combined with a CT-2 system,functions as a telecommunications system that allows system subscriberswith CT-2 handsets to both make outgoing calls and receive incomingcalls. In the telecommunications system of this invention, the CT-2subscribers are provided with pagers. In some preferred versions of thisinvention, the pagers are built into the CT-2 handsets. The CT-2handsets are also provided with an autodial circuit that allows thesubscriber to dial a number, his private paging system telephone number,with the press of a single button. When a call is made to one of thesubscribers to this system, the call is parked on hold while a page isbroadcast to the subscriber's handset. Upon receipt of the page, thesubscriber can complete the call by actuating the autodial button on thehandset. This causes the CT-2 system to access the paging terminalthrough the subscriber's private number; the paging terminal thenconnects the caller to the subscriber so that they can converse.

The telecommunications system of this invention provides a mechanism forconnecting callers directly with the subscribers they are trying toreach. Callers do not have to wait for subscribers to return theircalls. Subscribers can, if they elect, be immediately connected toparties who are trying to reach them.

When the paging system is combined with a CT-2 system, thetelecommunications system of this invention allows subscribers to bothmake and receive calls through portable CT-2 handsets. Since pages arebroadcast on a system-wide basis, the telecommunications system of thisinvention does not have to be provided with expensive tracking equipmentthat constantly monitors the location of each handset. Since the CT-2portion of the system operates over frequencies that are separate fromthose over which cellular systems operate, the system of this inventionmakes call-or-be-called portable telephone services available to alarger population.

Other features of the telecommunications system of this inventionenhance its utility to subscribers and callers alike. In the event asubscriber does not complete a phone connection to a caller, the callercan be invited to leave a voice-mail message that the subscriber canretrieve at his convenience. In some versions of the invention, thesubscriber can forward commands to the paging terminal to indicate hiswillingness or unwillingness to accept page-connect pages. Depending onthe command generated by the subscriber, the paging terminal will eithersend a page-connect page or simply invite the caller to leave a message.The system can further be constructed so that a caller may first berequired to enter a command before a page-connect page will betransmitted. This will allow a subscriber to select the callers fromwhom he will accept a page-connect page. If the subscriber wants toaccept page-connect pages from an individual, the subscriber will givethat individual his public paging system number and his page-connectpage access code. If the subscriber wants to accept only basic pagesand/or voice mail from an individual, the subscriber will give thatindividual only his public paging system number.

The system may also be configured to give the caller or the subscriberthe option of proceeding with the page-connect call. For example, whenthe caller first tries to access the subscriber through the system, thesystem can give the caller the option of leaving a message in thesubscriber's voice mailbox, being connecting to a third party such asthe subscriber's secretary, or having the page-connect page generated inanticipation of being connected to the caller. The system can also bedesigned to provide the subscriber with some identification of thecaller along with the page-connect page. These versions of the systemmay further be configured to give the subscriber the choice of beingconnected to the caller or forwarding the call to another destination.

Another advantage of this system is that it allows the system operatorto offer potential subscribers various classes of service. Individualscan take advantage of simply the basic paging service, the more advancedpage-connect paging service wherein the individual has a CT-2 handset,or any range of services therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is defined with particularity in the appended claims. Theadvantages of this invention may be understood by referring to thefollowing detailed description in which:

FIG. 1 is a block diagram illustrating the main components of thetelecommunications system of this invention;

FIG. 2 is a block diagram illustrating relevant subunits of a pagingsystem as incorporated into the telecommunications system of thisinvention;

FIG. 3 illustrates the structure of a batch of pages that are broadcastby the paging system of this invention;

FIG. 4 is a detailed block diagram view illustrating how a pulse codemodulation (PCM) highway connects the various subunits of the pagingsystem of this invention to allow the transfer of digitized voicesignals therebetween;

FIG. 5 illustrates how, by time-division multiplexing, signals frommultiple conversations are exchanged simultaneously over one of theindividual PCM highways of this invention;

FIG. 6 is a block diagram of the various tasks that are executed by thepaging system of this invention, wherein those tasks are generallyillustrated in modular form;

FIG. 7 illustrates the subscriber library that is maintained by thepaging system of this invention and further specifically illustrates thecontents of an individual subscriber record in the library;

FIG. 8 illustrates the trunk pair table that is maintained by the pagingsystem of this invention and further specifically illustrates thecontent of an individual trunk pair record in the table;

FIG. 9 illustrates a list of paging requests that is maintained by thepaging system of this invention and further illustrates the manner inwhich new pages are placed in the list by a prioritization subtask;

FIGS. 10A through 10E, taken together, represent a flow chart depictingthe steps performed by the paging system of this invention in order toconnect a page-connect paging system subscriber with an individualcalling the subscriber;

FIG. 11 illustrates in block diagram an alternative paging systemterminal of this invention;

FIG. 12 illustrates in block diagram how the paging system of FIG. 11can be configured;

FIG. 13 represents a flow chart of the steps performed by the pagingsystem of this invention when the caller option task is executed;

FIG. 14 represents the structure of the outcall code table that isreferenced by the call notifier task of this invention;

FIG. 15 represents the structure of the time table that is referenced bythe call notifier task of this invention; and

FIG. 16 represents a flow chart of the steps performed by the pagingsystem of this invention when the subscriber option task is executed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The telecommunications system of this invention is illustrated in blockdiagram by FIG. 1 including a paging system and a cordless telephone-2(CT-2) wireless communications system. Persons that subscribe to thesystem each carry a small, portable handset 26, that serves as atransceiver over which audio, voice, signals can be exchanged throughthe CT-2 system. Integral with the handset 26 is a pager 27, which is asmall receiver for receiving signals from the paging system. The pagingsystem includes a paging terminal 28 and a set of paging stations 30.The paging terminal 28 is connected to the publicly switched telephonenetwork (PSTN) 32 for receiving telephone calls from individuals tryingto access the system subscribers. When such a call is received, thepaging terminal 28 creates a message, called a page, for the subscriberand forwards the page to the paging stations 30. The paging stations 30broadcast the page, which is received by the pager 27.

The CT-2 system includes a set of base stations 36 that are low-poweredtransceivers configured to exchange signals with the handsets 26. Someof the base stations 36 may be geographically located with pagingstations 30; other base stations may stand alone. Each base station 36is connected to the publicly switched telephone network 32 and serves asthe signal interface between the network 32 and the handset 26 withwhich a radio link has been established. When a system subscriberreceives a page, he/she can access the caller by activating the handsettransceiver. A telephone link will be established between handset 26 andthe paging terminal 28 through an adjacent base station 36 and thepublicly switched telephone network 32. When the subscriber's callreaches the paging terminal 28, the paging terminal connects the callerto the subscriber so that the two can converse in a normal manner.

The paging system of this invention is described in greater detail withreference to FIG. 2. The paging terminal 28 comprises a terminal capableof generating pages and serving as a voice-mail storage and retrievalunit. One such terminal is the GL3000 Message Management System andVoice Retrieval System manufactured by Glenayre Electronics Ltd. ofVancouver, British Columbia, Canada. The paging terminal 28 includes oneor more direct inward dial (DID) cards 42 that function as the interfacebetween the paging system and the publicly switched telephone network32. One or more universal output encoder (UOE) cards 44 forward pages 34to the paging stations 30 for broadcast. The paging terminal 28 has atleast one voice storage board (VSB) 46 that serves as a temporary bufferto store voice messages for replay out to the system subscribers throughthe DID cards. The VSB also contains a number of set, prerecorded voicemessages, such as greetings, system instructions, and/or system stateannouncements that are selectively played to the callers or the systemsubscribers. A call progress tone (CPT) card 47 includes a set ofcomponents that generate various audio tones that are selectively playedto system subscribers and other individuals who access the system.

The overall operation of the paging terminal 28 is controlled by acentral processing unit (CPU) 48. A hard drive 50 serves as the memorythat contains information, such as a subscriber record 108 (FIG. 7), foreach subscriber, which lists the services that the subscriber uses. Thehard drive 50 also functions as the memory in which the voice messagesthat are left for the subscriber are stored. The writing of informationinto and the reading of information out of the hard drive 50 arecontrolled by a disk controller card (DCC) 52.

The CPU 48 and the DCC 52 are connected by a common communicationspathway, referred to as the VME bus 54. A second bus, a data and control(DAC) bus 56 serves as the pathway over which data and control signalsare transferred to and from the CPU 48 and the DID cards 42, the UOEcards 44, the VSB 46, and the CPT card 47. A switch card 58 serves asthe interface between the VME bus 54 and the DAC bus 56. The switch card58 converts the signals passing over each of the buses 54 and 56 into anappropriate format so that the signals can be distributed over the otherbus. Digitized voice signals are transferred between the VSB 46 and theVME bus 54 over a direct-memory access (DMA) bus 60. A buffer memoryinterface card (BMIC) 62 provides a high-speed window between the VMEbus 54 and the DMA bus 60 to allow the transfer of signals therebetween.Digitized audio signals, including voice signals, are transferredbetween the DID cards 42, the UOE cards 44, the VSB 46 and the CPT card47 over a pulse code modulation (PCM) highway 64. The switch card 58regulates the flow of data over the PCM highway 64 pursuant toinstructions generated by the CPU 48.

In one preferred embodiment of the invention, each DID card 42 iscapable of being connected to two trunk lines 66 that extend from thePSTN 32 to the paging terminal 28. Depending on the configuration of theparticular trunk line 66, it may serve as a communications path foranywhere between 100 to 100,000 different telephone numbers. When a callis forwarded from the central office to a DID card 42, the "header"portion of the call contains signals that identify the phone numberbeing called. This header material may be in the form of a set ofdistinct audio tones (dual-tone multifrequency (DTMF) pulses) or a setof on-off-on-off (rotary), pulses. Processing equipment on the DID card42 converts the header information into a digital format. The DID card42 transmits the header information, as part of a message announcing thecall, to the CPU 48. If the CPU 48 determines that the call is to a"valid" subscriber number, the DID card 42 is instructed to establish aconnection to the caller. In response to such a command, the DID card 42answers the call to establish a connection to the caller. The DID card42 is further provided with processing circuitry that converts the audiosignals received from the caller, which are in an analog format, to adigital format. The digitized audio signals are then transmitted by theDID card 42 to other subsystems of the paging terminal 28 over the PCMhighway 64. The DID card 42 is further capable of converting digitizedaudio signals received over the PCM highway into an analog format. Theanalog audio signals are distributed by the DID card 42 through thetrunk lines 66 and the PSTN 32 to the telephone over which the call tothe system was made in order to produce recognizable speech. In someversions of the invention, the DID cards 42 are further provided withthe capability of making outgoing telephone calls. These DID cards 42are provided with tone generators capable of generating DTMF pulses overthe trunk lines 66 in order to place telephone calls to specificlocations.

The UOE cards 44 generate paging signals to the paging stations 30 thatare then rebroadcast as the pages 34. In one form of paging system, thepaging terminal 28 assembles a block of pages 34 into a single messageknown as a batch 68, illustrated by FIG. 3. Each batch 68 includes apreamble message 70 that serves to identify the transmission as a pagingmessage. A synchronization word 72 follows the preamble message 70. Thesynchronization word 72 comprises a set of signals that the pagers 27 inthe handsets 26 use to regulate their processing circuitry so that theremainder of the batch 68 will be properly processed. Following thesynchronization word 72 are a set of code words (CWs) 74. There are twotypes of code words, address code words 74a and data code words 74b.Each address code word 74a contains the address of the pager assigned toone specific subscriber. The data code words 74b follow the address codewords 74a. The data code word 74b contains the actual page for theparticular subscriber's pager. Processing circuitry inside the pager 27monitors the received paging batches 68 for an address code word 74athat contains the address for that subscriber. When such an address codeword 74a is received, the pager 27 reads the following data code word74b for the paging data that is being sent to that subscriber. Theprocessing circuitry in the pager 27 then generates the page based onthe information contained in the data code word 74b. The data requiredto create some pages, such as long alphanumeric pages or voice pages,may be greater than the data that can be fitted in a single data codeword 74b. In this event, it may be necessary to transmit multiple datacode words 74b so that the entire page can be presented to thesubscriber.

In one preferred embodiment of the invention, batches 68, except for anyvoice component thereof, are assembled entirely by the CPU 48 andforwarded to the various UOE cards 44. Digitized audio signals that formthe voice pages are forwarded to the UOE cards 44 from the VSB 46 overthe PCM highway 64. These signals are placed in the batches 68 by UOEcards 44 pursuant to commands generated by the CPU 48. Each UOE card 44controls the forwarding of the batches 68 that are transmitted by thepaging stations 30 over one particular carrier frequency. The batches 68transmitted by any one particular UOE card 44 can, however, betransmitted to the various paging stations 30 over differentcommunications links. For example, the batches transmitted by one UOEcard 44 can be forwarded to some paging stations 30 over a radio link138 (FIG. 1 ), over the PSTN 32, and/or over a dedicated fiber-optictransmission network (not illustrated). The UOE cards 44 forward thebatches 44 to the associated paging stations 30 at a rate at whichprocessing equipment integral to the paging stations is able to acceptthe information.

While in some paging terminals 28 each signal used to form a batch 68 isinitially generated by the CPU 48, there is no requirement that allterminals operate in this manner. Some terminals 28 can be constructedso that the UOE cards 44 insert the preamble message 70 andsynchronization word 72 on the front of each batch 68. Moreover, someUOE cards 44 can further be provided with means for producing tonesignals that regulate some characteristic of the rate at which thepaging stations 30 broadcast the pages. For example, some UOE cards 44are capable of generating control tones that are used to establish thecarrier frequencies over which the pages 34 are broadcast. Certain UOEcards 44 can also be equipped with circuitry for generating test signalsthat are used to evaluate the performance of the paging stations 30.

The VSB 46 facilitates the transfer of the digitized voice signalsbetween the DMA bus 60 and the PCM highway 64. Included on the VSB 46are components for converting signals between the format over which theyare broadcast on the DMA bus 60 and the format over which signals arebroadcast on the PCM highway 64. The VSB 46 also includes a set ofbuffers in which the voice signals are temporarily stored before theyare distributed over the DMA bus 60 or the PCM highway 64. Typically,messages for a subscriber's mailbox are first stored in the VSB buffersprior to the forwarding of the messages to the hard drive 50 over theDMA bus 60. When messages are retrieved for play, or retrieved fortransmission as a voice page, they are also first stored on the VSBbuffers prior to their broadcast over the PCM highway 64. Some messages,such as notices a subscriber wants broadcast or customized greetingsthat are generated by a subscriber, can consist of multiple-messagesegments. When such messages are to be played, the individual messagesegments are first concatenated in the VSB buffers. Once the completemessage has been assembled, it is broadcast over the PCM highway 64 tothe appropriate destination.

The VSB 46 further includes a section of memory in which standard systemmessages are always stored. These messages include system greetings,instructions and/or mailbox status information that is frequently playedout to system subscribers and other individuals who access the pagingsystem. These messages are contained in the system hard drive 50. Whenthe paging terminal 28 is initialized, these messages are uploaded intothe VSB 46 for quick access. The distribution, or play, of thesemessages is controlled by commands generated by the CPU 48.

The CPT card 47 contains a set of circuits for generating a number ofaudio tones that can be selectively played when an individual calls thesystem. One form of CPT 47, for example, is capable of generating fivedistinct tones. A ring tone can be generated in order to give the callerthe impression that the paging terminal 28 is in the process ofcompleting some portion of the call. A busy tone is generated to informthe caller that, for some reason, the call cannot be completed. Ananswer tone can be generated to serve as an instructionless announcementthat the caller can enter commands into the system. In other words, theanswer tone is generated to inform system subscribers and otherknowledgeable individuals that a set of commands or data must be enteredin order for the operation of the system to proceed. Usually commandsare entered into the paging terminal 28 by "overdialing," which is theact of generating one or more DTMF or rotary pulses after the call hasbeen connected. The processing equipment on the DID cards 42 decodes thecommands and broadcasts them to the CPU 48 over the DAC bus 56. Anothertone the CPT card 47 generates is an accept tone. The accept tone isplayed to a caller upon the entry of a voice message or overdialinstructions to acknowledge entry of the message or the instructions. Inversions of the system wherein there is an operator station (notillustrated), connected to the paging terminal 28, the CPT card 47 isfurther capable of generating an operator-alert tone to inform anattendant that someone needs assistance or that there is a voice messagethat needs to be transcribed into an alphanumeric page.

In one preferred embodiment of the invention, the switch card 58performs three functions. Specifically, the switch card 58 includes aclock circuit that generates the master clocking signal to which all theother subunits of the paging terminal 28 are synchronized. The switchcard 58 also includes conversion circuitry that facilitates the exchangeof signals between the VME bus 54 and the DAC bus 56.

The third function executed by the switch card 58 is the control ofdigitized voice-signal transfer over the PCM highway 64. Therelationship of the PCM highway to the other components of the pagingterminal 28 is first described with reference to FIG. 4, which depictsthe manner in which the PCM highway is connected to a DID card 42. ThePCM highway 64 actually is a collection of separate highways, identifiedas 64a, 64b, 64c, and 64d. Two of the individual highways, highways 64aand 64b, are transmit highways; the subunits of the paging terminal 28that broadcast digitized audio signals, the DID cards 42, the VSB 46,and the CPT card 47, do so over these highways. The other two individualPCM highways, highways 64c and 64d, are receive highways; the subunitsof the paging terminal 28 that receive digitized audio signals, the DIDcards 42, the UOE cards 44, and the VSB 46, do so over these highways.Signals are selectively broadcast and received over the individual PCMhighways 64a, 64b, 64c, and 64d by a process of time-divisionmultiplexing. As illustrated diagrammatically by FIG. 5; a particularperiod of time can be thought of as a frame 79 divided into a number oftime slots 80a, 80b, 80c, . . . 80n. In one version of this invention aframe 79 is a 125-microsecond time period that is divided into 32 timeslots 80, each 3.9 microseconds in length. The digitized audio signalsare transmitted between the subunits of the paging terminal 28 in theform of digitized words, wherein one or more words are transmitted to orfrom a particular subunit over a specific individual PCM highway 64a,64b, 64c, or 64d in a particular time slot 80a, 80b, 80c, . . . or 80n.For example, for one particular call, a DID card 42 may transfer avoice-mail message to the VSB 46 over highway 64b in time slot 80 number17. During the same time frame 79, the VSB card 46 receives thevoice-mail message over individual highway 64c in time slot 80 number25.

The transmission and reception of the digitized audio signals over theindividual PCM highways 64a through 64d are facilitated on each of thepaging terminal subunits by the signal-select circuitry shown in FIG. 4for a DID card 42. The circuit includes a CODEC 81, which is acoder/decoder capable of converting analog audio signals, voice signalsfrom a caller, into a digital format and digital signals into analogsignals. The digitized output signals from the CODEC 81 are applied to atransmit highway (TX HWY) select circuit 82 to which the individual PCMtransmit highways 64a and 64b are connected. The transmit highway selectcircuit 82 is a 2:1 multiplexer that selectively applies the outputsignals from the CODEC 81 to either one of the individual PCM transmithighways 64a or 64b. The actual time or, more particularly, the timeslot 80, in which the CODEC 81 transmits signals over one of the PCMtransmit highways 64a or 64b is controlled by a time slot assignmentcircuit (TSAC) 84. The TSAC 84 regulates when the CODEC 81 transmitsdigitized output signals so that they are inserted in the correct timeslot 80a, 80b, 80c, . . . or 80n. The PCM transmit highway selectionsestablished by the transmit highway select circuit 82 and the time slottransmission commands generated by the TSAC 84 are based on controlsignals generated by the CPU 48.

Digital voice signals received over the individual PCM receive highways64c and 64d are processed in a similar manner. A receive highway (RXHWY) select circuit 86, another 2:1 multiplexer, selectively applies thesignals from either one of the individual PCM receive highways 64c or64d to the CODEC 81. The TSAC 84 regulates the time periods or, moreparticularly, in which time slot 80a, 80b, 80c, . . . or 80n the CODEC81 converts the incoming digital signals into analog signals suitablefor replay to a conventional telephone. The time slot selections made bythe TSAC 84 and the PCM receive highway connections established by thereceive highway select circuit 86 are based on control signals generatedby the CPU 48.

The switch card 58 facilitates the exchange of digitized voice signalsover the individual PCM highways by transferring information from thePCM transmit highways 64a and 64b to the PCM receive highways 64c and64d. As depicted in FIG. 4, the switch card 58 includes a buffer 88 towhich the individual PCM highways 64a, 64b, 64c, and 64d are connectedand a cross-point switch 90 that is connected to the buffer. The buffer88 temporarily stores the digitized voice signals that are supplied toand transmitted from the switch card 58. The cross-point switch 90transfers the digitized voice signals from a time slot 80a, 8b, 80c, . .. or 80n in any one of the individual PCM transmit highways 64a or 64bto a time slot in one of the individual PCM receive highways 64c or 64d.The cross-point switch 90 performs the signal transfers based oninstructions received from the CPU 48.

The CPU 48 includes a microprocessor (μP) 92 that controls the overalloperations of the paging terminal 28. The CPU further includes a memory94 that contains instructions that are executed by the microprocessor 92and data that are used by and/or generated by the microprocessor. In onepreferred embodiment of the invention, a Motorola® 68030 32-bitprocessor is employed as the microprocessor 92. The memory 94 includes32M bits of memory integrally associated with the microprocessor 92 andanother 64M bits of memory located on a separate memory card.

The tasks, or programs, that are selectively executed by the CPU 48 tocontrol the paging terminal 28 are described with reference to FIG. 6.Before discussing the individual tasks in detail, it should beunderstood that the microprocessor 92 is provided with an operatingsystem that allows multitasking, wherein the execution of multiple taskscan be interleaved with each other. Moreover, as described hereinafter,there is a priority under which the microprocessor 92 will determinewhich new task will be executed first. The task prioritization levelsare further used to evaluate whether or not a new task that needs to beperformed is of such importance that its execution should interrupt thetask that the microprocessor 92 is currently executing.

Generally, the CPU 48 performs application tasks 98 and support tasks100. The application tasks 98 are the tasks that control the actual callinterconnections, message storage and replay, and page generations thatare performed by the paging terminal 28. The support tasks 100 are theunderlying tasks that make execution of the application tasks 98possible. The support tasks 100 include the control of any printers,operator terminals, or other input/output devices that are connected tothe terminal 28 and the generation of data on these devices. Othersupport tasks include interface tasks that control interfaces to beestablished between the paging terminal 28 and other devices, such asalphanumeric paging attendant terminals, and/or other paging terminals.Other support tasks 100 generate reports regarding the operation of thepaging system and handle the processing of errors. The structure of theabove support tasks is generally known by those familiar withdata-processing equipment and will not be further described.

A support task 100 of particular relevance is the PCM highway manager102. This task controls the digitized voice-signal transfers that occurover the PCM highway 64. Specifically, the PCM highway manager 102maintains a set of tables (not illustrated) for each individual PCMhighway 64a through 64d indicating the availability of time slots 80a,80b, 80c, . . . and 80n for that highway. The PCM highway manager 102receives indications from other tasks, typically application tasks 98,that there is a need to have a digitized voice signal path between twopaging terminal subunits. In response to this indication, the PCMhighway manager 102 determines in which available time slot 80a, 80b,80c. . . or 80n and over which one of the individual PCM transmittinghighways 64a or 64b the transmitting subunit should forward thedigitized voice signals. The PCM highway manager 102 also determines inwhich time slot 80a, 80b, 80c. . . or 80n and over which individual PCMreceiving highway 64c or 64d the receiving subunit should receive thedigitized voice signals. The PCM highway manager 102 then directs themicroprocessor 92 to generate control signals to the appropriatetransmit highway select circuit 82, the appropriate receive highwayselect circuit 86, the appropriate TSACs 84, and the cross-point switch90 so that signal transfer will take place over the designated highways64a, 64b, 64c, or 64d in the designated time slots 80a, 80b, 80c, . . .or 80n.

The applications tasks 98 include a trunk task 104. The trunk task isresponsible for servicing all incoming calls made into the paging system28 and for generating any outgoing calls the system makes if the systemhas call-generating capabilities. The trunk task services incoming callsby referring to a subscriber library 106, now described with referenceto FIG. 7. The subscriber library 106 contains a set of subscriberrecords 108, each of which is associated with a separate subscriber.Each subscriber record 108 includes a public number (Pub. No.) field110, which allows the record to be identified by the subscriber's publicnumber. In some versions of the invention, the public number field 110may be the subscriber's actual public number. In other versions of thisinvention, the CPU 48 may maintain a library of subscriber publicnumbers, each of which further includes a pointer that indicates wherethe subscriber record 108 of that particular subscriber is located. Thesubscriber record 108 includes a service field 112 that identifies theparticular paging service to which that individual subscribes. Anindividual may subscribe to one or more of the basic paging services:tone paging, numeric paging, alphanumeric paging, voice paging, and/orvoice mail. There is a further set of feature fields (FFs) 114a through114e that indicate if the individual subscribes to certain features thatare associated with his general services. One feature field, forexample, indicates if the subscriber has a customized greeting that hehas recorded to invite callers to leave a message. There is a featurefield to indicate if a subscriber is a page-connect subscriber. Anotherfeature may indicate if the subscriber has a page-connect overdialauthorization. This feature requires a caller to overdial an access codebefore the trunk task 104 will initiate the page-connect paging process.The information contained in the feature fields 114a through 114efurther includes pointers that indicate where relevant data about thatsubscriber may be found. For example, the feature field for customizedgreetings will contain a pointer that leads to an address on the harddrive 50 where the subscriber's customized greetings can be found. Thefeature field for page-connect overdial authorization will contain anindication of where that subscriber's private overdial access code islocated. Each subscriber record 108 further includes a cap code (CC)field 116 and an encoding (ENC) field 118. The cap code field 116contains the identification number, the address of the pager 27,assigned to that subscriber. The encoding field 118 indicates the codingformat for the pages 34 that are to be broadcast to the pager 27.

Subscribers who use the page-connect service and certain othersubscribers will further have a private number (Priv. No.) field 120.The private number field 120 identifies a private phone number that isassigned to the subscriber. The subscriber records for these subscribersmay also include a page-connect availability feature field, for example,feature field 114e. The page-connect availability field 114e contains anindication of the particular subscriber's willingness to acceptpage-connect pages as opposed to other pages. The subscriber can entercommands into the paging terminal 28 to change the state of thepage-connect availability field 114e to indicate his/her willingness orunwillingness to accept page-connect pages.

It should be understood that the foregoing description of a single,monolithic subscriber record 108 is illustrative and not meant to belimiting. The various fields may each be located in their own librariesthat can be accessed by reference to pointers located in the subscriberrecord 108. Some fields may even be grouped together in their ownlibrary. For example, there may be a page-connect page library. Thislibrary would contain both the private number fields 120 and thepage-connect availability fields 114d for each page-connect subscriber.The individual records in these libraries would be accessed by referenceto an address that is associated with both the subscriber's publictelephone number and the subscriber's private telephone number.

The trunk task 104 performs page-connect paging by reference to a trunkpair table 119 depicted by FIG. 8. Trunk pair table 119 maintains atrunk pair record 121 for each page-connect call the paging terminal 28is currently processing. Each record 121 includes a public trunk field122, a private trunk field 123 and a resources allocation field,represented as a single field 124. The public trunk field 122 containsthe public number of a subscriber for whom a page-connect page has beenor will be generated. The private trunk field 123 contains the privatenumber of the subscriber. The resource allocation field 124 contains anindication of the PCM highway resources that are used to established afully duplexed audio signal link between the caller and the subscriber.As will be described, each trunk pair record 121 is formed during theprocessing of a call to a page-connect page subscriber.

By reference to the subscriber record 108 and the trunk pair table 119,the trunk task 104 processes incoming calls to the paging system. Basedon the telephone number forwarded to the CPU 48 by the DID card 42, thetrunk task 104 initially determines if it is a valid call to anauthorized system subscriber and if the call is from the subscriber'spublic telephone number or his/her private telephone number. If the callis over an invalid telephone number, a number not assigned to anyparticular subscriber, the trunk task 104 will arrange for the retrievaland play of a message indicating that the caller dialed an invalidnumber and then disconnect the call. If the call is over a subscriber'spublic phone number, the trunk task will play the appropriate messagesthat the subscriber designated for his services. For example, if thepaging system is functioning as a voice-mailbox, the trunk task willplay an appropriate greeting to invite the caller to leave a message. Ifthe system serves as a pager, the trunk task 104 will invite the callerto leave a page by overdialing data or, for alphanumeric and voicepages, by leaving a message. If the called system customer is apage-connect page subscriber, the trunk task will execute a page-connecttask 126, described in detail hereinafter, to try to connect the callerwith the subscriber. If the caller has accessed the paging terminal 28to page a subscriber, the trunk task 104 will generate a page request130 (FIG. 9), which is an instruction directing the formation of a pagefor transmission to the subscriber. Each page request 130 includes apointer that indicates where the necessary information to create thepage can be found. The pointer integral with the page request 130 may,for example, indicate the address of the subscriber record 108 for thesubscriber. As described hereinafter, another task running on thecentral processing unit 48 accesses the subscriber record 108 for theinformation necessary to create the page for the subscriber.

The trunk task 104 may also include a caller option task 125 or asubscriber option task 133. As described hereinafter, the caller optiontask 125 allows the caller to proceed with the generation of thepage-connect page in anticipation of being connected to the subscriberor having the call routed to another destination such as subscriber'svoice mailbox or secretary. The subscriber option task 133 identifiesthe caller to the subscriber as part of the page-connect process andthen gives the subscriber the options of accepting the call, routing thecall to another destination, or disconnecting the call.

If the caller is a system subscriber, then, based on overdial commandsentered by the subscriber, the mink task 104 will initiate the replay ofstored messages to the subscriber. Alternatively, depending on thecommands that have been entered, the trunk task may collect messagesleft by the subscriber and distribute them to other parties. If thecaller is a subscriber who uses the page-connect page service, the trunktask 104 initially references the trunk pair table 119 to determine ifit includes a trunk pair record 121 that contains a private trunk field123 with that subscriber's private number. If there is such a record121, the trunk task 104 will connect the subscriber to the caller.

Pages are actually created by a queuing and coding (Q & C) task 128. Thequeuing and coding task receives the page requests 130 from the trunktasks 104. Based on the pointer that is integral with the page request130, the queuing and coding task 128 accesses the subscriber's record108 and, based on the information contained therein, actually generatesthe page. The queuing and coding task 128 also places the page into theappropriate format so that the page can be properly processed by theprocessing equipment contained in the pager 27. The queuing and codingtask 128 further groups pages together in batches 68.

As part of the page formation process, the queuing and coding task 128maintains a list 129 of paging requests 130a, 130b, 130c. . . and 130n,depicted by FIG. 9, for pages that need to be created. The page requests13 0a through 130n are processed in the order of their locations on thelist 129, wherein the first page request 130a is processed first. Thepage requests 130 are placed on the list 129 by a prioritization subtask132, which is a subtask of the queuing and coding task 128. Normally,the prioritization subtask 132 places a newly received paging request130z on the bottom of the paging request list 129. However, if headerinformation contained in the new paging request 130z indicates that therequest is for a page-connect page, the prioritization subtask 132places that request on the page request list 129 at the head of all thenon-page-connect page requests, after the last-created page-connect pagerequest 130. This ensures that the page-connect page is generated andbroadcast first to minimize the amount of time that the caller has towait for the subscriber to respond.

The queuing and coding task 128 also includes a page delete subtask 127depicted in FIG. 9. The page delete subtask 127 can selectively deletepage requests, as shown by arrow 131 to page request 130b. Page deletesubtask 127 is selectively employed in response to commands from thetrunk task 104 that there is no need to create and transmit a particularpage. For example, when the trunk task 104 detects that a caller who hasaccessed a page-connect page subscriber has hung up before the systemhas generated and transmitted a page, the trunk task will direct thepage delete subtask 127 to delete the page request for that subscriber.This prevents the generation of a page to a subscriber when there is nocalling party waiting to connect to the subscriber.

In some versions of the invention, the queuing and coding task 128 mayinclude a call notifier task 139 (FIG. 6). As will be describedhereinafter, the call notifier task 139 selectively forwards a page to aparticular destination, for example, either the subscriber's pager or anoffice telephone, based upon when the call is received. Versions of thesystem that include the call notifier task 139 are provided with DIDcards 42 capable of placing outgoing telephone calls.

Pages generated by the queuing and coding task 128 are forwarded to aUOE task 134. The UOE task 134 selectively downloads the formatted pages34 onto the appropriate UOE card 44 so that the pages can be broadcastover the appropriate paging stations 30. The UOE task 134 furtherreceives messages from the UOE cards 44 that indicate when specificbatches 68 of pages have been broadcast. When a particular page is avoice page, the UOE task 134 further sends a message-retrieveinstruction to a voice storage task 136, described so that the messagewill be transferred from the hard drive 50 to the appropriate UOE card44 for broadcast as a page.

The voice storage task 136 performs all transfers of digitized voicesignals between the VSB 46 and the hard drive 50. The voice storage task136 prevents conflicts between individual subtasks that are beingexecuted and that share the same stored voice signals. The voice storagetask 136 is further set to control the storage and retrieval ofdigitized voice signals so that the DCC 52 is as efficient as possible;this reduces bottlenecks that could otherwise occur as pan of thestorage and retrieval process.

The central processing unit 48 executes the trunk task 104 beforeperforming any other tasks. In other words, the processes performed bythe trunk task 104 are considered to have the highest priority. Thesecond highest priority processes are the message storage and retrievalprocesses performed by the voice storage task 136. The forwarding ofpages by the UOE task 134 is the next highest priority task to beexecuted. The lowest priority application processes are those associatedwith the formation of the pages and forwarding batch 68 performed by thequeuing and coding task 128. The ancillary support tasks 100 that arenot directly associated with the processing of calls to the pagingterminal 28 are the lowest priority tasks and are executed last by thecentral processing unit 48. These tasks 100 include tasks associatedwith printing maintenance and system operation tasks.

Referring again to FIG. 1, additional detail regarding the paging systemis set forth. After the batches 68 of pages 34 are created, they areforwarded to the individual paging stations 30. As showndiagrammatically, the pages may be forwarded over a radio link, throughthe PSTN 32, or by any other convenient communications means. Forexample, in some paging systems, the pages may be sent to the individualpaging stations 30 over a microwave relay network. Once a batch 68 ofpages 34 is received at the paging stations 30, it is broadcast forreception by the pagers 27.

The CT-2 portion of the telecommunications system of this invention isalso described with respect to FIG. 1. The "fixed" part of the CT-2system is the base stations 36. Each base station 36 comprises atransceiver, approximately 0.5×1.0×2.0 meters in size, which iscontained in a weatherproof housing to facilitate its mounting outdoors.Each base station 36 is further connected to the PSTN 32. Each basestation 36 includes processing circuitry to read header informationtransmitted by the handset 26. The processing circuitry uses thisinformation to place a call to the party being accessed by thesubscriber. The header information is further used by the base station36 to identify the subscriber so that appropriate billing informationcan be forwarded to a billing office (not illustrated). One such basestation 36 is the Concept 2030 manufactured by GPT Telepoint, Coventry,United Kingdom.

A suitable CT-2 handset 26 is the Concept 2000, also manufactured by GPTTelepoint. In current CT-2 systems, a typical handset 26 can be used toexchange signals with a base station 36 that is within a range ofapproximately 200 to 400 meters. The handset 26 of this inventionfurther includes an autodial function. This function causes the handset26 to automatically dial and transmit a specific number, thesubscriber's private number, when the subscriber presses a specificbutton (not illustrated) on the handset.

The handset 26 of the telecommunications system of this inventionincludes a pager 27 designed to receive pages 34 from the pagingstations 30. A suitable pager 27 that can be built into the handset 26is the Bravo™ pager manufactured by Motorola of Schaumburg, Ill. Inorder to ensure that the handset transceiver and the page receiver donot interfere with each other's operation, they are selected to operateat substantially different frequencies. In one preferred version of thisinvention, the handset 26 and CT-2 base stations 36 exchange signals atfrequencies between 864 and 868 MHz. and the pager 27 receives pages 34from the paging stations 30 at approximately 150 MHz.

The flow charts of FIGS. 10A through 10E illustrate the manner in whichthe telecommunications system of this invention is used to offerpage-connect paging services to the system subscribers. Initially, thepaging terminal 28 receives an incoming call over a subscriber's publicphone number as indicated by a call-receive step 152. In thecall-receive step 152, the DID card 42 over which the call is receivedinitially forwards the "incoming" telephone number to the CPU 48. Thetrunk task 104 is executed to determine if the number is valid and if itis the subscriber's public number or private number. During this time,trunk task 104 directs the CPT card 47 to generate a ring signal that isplayed to the caller.

After it is determined that the call is to a subscriber's publictelephone number, the trunk task 104 determines if the subscriber is apage-connect subscriber as indicated by step 154. This evaluation isperformed by reading the subscriber-record service fields 114a to 114dto determine the features to which the particular individual subscribes.If the indication is that the individual is not a page-connectsubscriber, the trunk task 104 proceeds to invite the caller to use oneof the other services, i.e., paging or voice-mail, that the subscriberselected, as depicted by an execute-other-services step 155. If thesubscriber is a page-connect page subscriber, the page-connect task 126is executed. Based on the information contained in one of the othersubscriber-record feature fields, the page-connect task 126 determinesif the subscriber has a private access code, as represented by step 156.If the subscriber does not have this feature, the page-connect task 126proceeds with the page-connect process. If the subscriber has thisfeature, the page-connect task 126 waits a selected time for theappropriate access code to be entered, represented by step 158. In someversions of the invention, the caller's cue to enter the access codewill be the play of the answer tone by the CPT card 47. In otherversions of the invention, the cue may be an innocuous message such as"Leave your message now" that is played to the caller. If the callerdoes not enter the correct access code, the page-connect task 126 ceasesto execute and the trunk task 104 performs the execute-other-servicesstep 155.

If the correct access code is entered, the page-connect task 126continues to execute. The page-connect task then determines if thepaging system is currently handling a preselected maximum number ofpage-connect pages as represented by step 164. This evaluation is madebecause, even though the paging terminal 28 is capable of handling alarge number of page-connect calls, the trunk lines 66 connected to theterminal from the PSTN 32 may not be able to handle both large numbersof page-connect calls and calls that are paging requests and/orvoice-mail messages to other system subscribers. Accordingly, in orderto prevent monopolization of the paging system by page-connectsubscribers and their callers, a determination is made as to whether ornot the system is currently processing the maximum number ofpage-connect pages. For example, a system with 10,000 subscribers, ofwhom 1,000 are page-connect subscribers, can be configured so that atany given time there are only 10 to 20 page-connect callinterconnections. This determination is made by reviewing how manypage-connect calls the system is currently handling as indicated by thecount contained in a page-connect page count field (not illustrated). Ifthe system is processing the maximum number of page-connect pages, thesystem terminates execution of the page-connect task 126 and proceeds toan alternative-services step 166. In the alternative-services step 166,the system will generate a "We are unable to connect to your party atthis time" message to the caller, and then offers to generate aconventional page and/or invites the caller to leave a voice-mailmessage. After the caller has taken advantage of thealternative-services step 166, the call is disconnected.

If the paging system still has the capability of handling additionalpage-connect pages, the page-connect task 126 initially performs apage-connect page count-increment step 168. In step 168, thepage-connect task increments by one the count stored in the page-connectpage count field. This field is incremented immediately after themaximum-number-of-pages determination step 164 because, if the systemwas processing one less than the maximum number of page-connect pages,then the immediate incrementation of the counter prevents later callersfrom establishing page-connect pages, which would result in themonopolization of the system.

The page-connect task 126 then performs a subscriber-availabilitydetermination, represented by step 170. This evaluation is a two-parttest. Initially, the page-connect task reviews the subscriber'spage-connect call availability field 114e to establish whether or notthe subscriber is willing to accept a page-connect page. Thepage-connect task then reviews the trunk pair table 119 to determine ifone of the trunk pair records 121 contains a public trunk field 122 withthe subscriber's public number. If there is such a record 121, it is anindication that the subscriber already has a page-connect call waitingor is actually engaged in a page-connect call. In step 172, thepage-connect page count field is decremented by one to indicate that thesystem is capable of handling an additional page-connect page. Thesystem then ceases to execute the page-connect task 126 and proceeds tothe alternative-services step 166.

If the results of subscriber-available step 170 indicate that thesubscriber is available to accept a page-connect page, the centralprocessing unit 48 creates a new trunk pair record 121 in the trunk pairtable 119 as represented by step 174 (FIG. 10B). When the new trunk pairrecord 121 is written into the table 119, the subscriber's public numberis written into the public trunk field 122 and the subscriber's privatenumber is written into the private trunk field 123.

After the execution of the above-described steps, the system is ready toproceed to a generate page-connect-page step 178, as will be describedhereinafter. There may be a slight pause in the execution of thepage-connect task 126 before step 178 is performed so that overall therewill be a delay of approximately three to five seconds between theinitial receipt of the call and the generation of the page. This delayis to give the caller an opportunity to hang up or overdial a request toenter a voice message and/or a page other than a page-connect page. Thistime delay may be established by the system operator and, thus, is thesame for ever,/subscriber. Alternatively, it may be set by thesubscriber. In the latter case, each page-connect page system subscriberrecord field 108 will include one or more feature fields 114a through114d, which indicate the delay-before-page time period for theassociated subscriber. In this case, this field is read (step notshown), during the execution of the page-connect task 126 to determinewhen the page-generate step 178 should be performed.

In the page-generate step 178, the page-connect task 126 directs thetrunk task to send a page-connect-page page request to the queuing andcoding task 128. Upon receipt of the page request, the prioritizationsubtask 132 reads the page request 130z and recognizes that the requestis for a page-connect page and that the request should be handledimmediately. The prioritization subtask 132 places that request beforeany previously generated non-page-connect page requests 130 that mayalready be in the page request list 129 so that it receives priorityprocessing by the other sections of the queuing and coding task 128. If,prior to the generation of the page, the caller hangs up, the trunk taskdirects the page delete subtask 127 to remove that page request 130 fromthe page request list 129. The trunk pair record 121 for that call iserased, the page-connect page count field is decremented, and thepage-connect task 126 stops executing.

Once a page request 130a makes it to the head of the page request list129, the other sections of the queuing and coding task 128 generate thepage and forward it to the UOE task 134. The UOE task 134 then downloadsthe page into the appropriate UOE card 44. The UOE card 44, in turn,forwards the page to the paging stations 30. The page is then broadcastfor reception by the pager 27 in the subscriber's handset 26 asrepresented by a transmit page-connect page step 180.

During the first 30 to 40 seconds of the caller's phone call, the periodof time in which the page is formed and first transmitted to the pagingstations 30, the paging terminal 30 directs the CPT card 47 to generatea ring signal. This is to provide the caller with the normal "ringing"sound one hears while waiting for a called party to pick up the phone.After this initial period, if the subscriber has not responded, the CPU48 will execute a page-announce step 182. In this step 182, thepage-connect task directs the play of a "Please wait for your party toconnect" message or a customized message. This message is generated toinform the caller that the system has generated a page in response tohis/her call to the subscriber. After the play of this message, thesystem will continue to play a ring tone, or play music to the caller,to provide an indication that the caller is still connected to thesystem.

While the caller is waiting for the subscriber to respond, thepage-connect task 126 monitors how long the caller has been waiting, or"parked," represented by step 185. This monitoring is based on theelapsed time as indicated by a dwell timer that is constantly advancedas indicated by step 184. The timer along with a companion option-outfield (not illustrated), are initially set to zero when a page is firstgenerated. When the end of a park period is reached, an option-outsequence is initiated. The option-out sequence, as depicted by FIG. 10C,starts with a determination of the number of times the sequence has beenexecuted as represented by step 188. In step 188 the count contained inthe option-out field is compared to a maximum count value maintained bythe page-connect task 126. If the system has performed the sequence lessthan the maximum number of times, the system performs a play-option-outmessage step 190. In this step 190, the page-connect task directs thesystem to play a "Please continue waiting or press * to leave a message"message to the caller. This informs the caller that he can continuewaiting or simply leave a message. The system then monitors the line, asrepresented by step 192, to determine if the caller has pressed "*" toleave a message. The dwell timer is also set to zero, as represented bystep 193, and the advancement sequence is repeated.

If the caller elects to leave a message, the system will initiate anexit procedure that starts with a page-connect page count-decrementfield step 196, wherein the page-connect page count field isdecremented. The system then erases the trunk pair record 121 for thecall in the trunk pair table 119, stops executing the page-connect task126, and performs an alternative-services step 197 wherein the caller isinvited to leave a voice message.

If the caller is on the last option-out sequence, as indicated by themaximum-play determination step 188, the system proceeds to a sign-offsequence, which starts with a page-connect page count-decrement fieldstep 202 during which execution of the page-connect task 126 stops. Thesystem then proceeds to a sign-off step 204. In this step 204, thesystem plays a message informing the caller that the paged subscriberhas not responded and gives the subscriber one last opportunity to leavea voice-mail message. Also in step 204, the trunk pair record 121 forthe call in the trunk pair table 119 is erased. After any message isleft, the call is disconnected.

How any particular pager 27 responds upon receiving a page-connect pagewill depend upon the construction of the particular pager. A tone pager27 will generate a specific sequence of tones or a single, specific,tone to indicate a page-connect page has been received. The display on anumeric or alphanumeric pager 27 will present a preconfigured messageindicating that a page-connect page has been received. A page-connectpage sent to a voice pager 27 will actually be a short message that isplayed to the subscriber to announce the page. Upon receipt of thepage-connect page, if the subscriber so desires, he can call the pagingsystem so as to be connected to the calling party. If the subscriber hasa CT-2 handset 26, all that is necessary to call the paging system is topress the autodial button on the handset. The CT-2 system will thenconnect the subscriber to the paging terminal over his privatesubscriber's telephone number through the PSTN 32.

As represented by the receive-call step 210 in FIG. 10D, upon receipt ofthe subscriber's telephone call at the paging terminal 28, the trunktask 104 handles the call in the regular manner. By reviewing thesubscriber records 108 and, in particular, the private number fields120, the trunk task determines that the call is from a subscriber overhis/her private line. The trunk task 104 then determines if entry of anaccess code is required to continue a call as represented by step 211.In step 211, by reference to the appropriate feature field 114a, 114b,114c, or 114d, the trunk task 104 determines if the subscriber has thesystem configured so that it is necessary to enter an access code beforecontinued use of the system over the private number can proceed. If itis necessary to enter an access code, the mink task 104 waits for theentry of the code and determines if it is the correct code, asrepresented by steps 212 and 213, respectively. If it is not the correctcode, the trunk task 104 performs a disconnect procedure, represented bystep 214. In step 214, the subscriber may be given another opportunityto enter the correct access code and/or the system may inform the callerthat his request to access the system has been denied and disconnect thecall.

If no access code is required, or if the correct access code is entered,the system then reviews the trunk pair table 119 to determine if thesubscriber's private number is written into the private trunk field 123for one of the trunk pair records 121 to determine if there is a callwaiting, as represented by step 215. If there is no call waiting, thetrunk task 104 waits for the subscriber to overdial a set of commandsignals, as represented by step 216, to indicate why the subscribercalled the system. The trunk task 104 then responds to those commands ina step 217.

If the trunk pair table 119 indicates that there is a call waiting, thenthe trunk task 104 initiates a page-connect connect process with aresource allocation step 218. In the resource allocation step 218, thePCM highway manager 102 (FIG. 6) is employed to establish the individualPCM highways 64a, 64b, 64c, or 64c and the time slots 80 in thosehighways over which the audio signals between the caller and the calledsubscriber will be transferred. Four PCM highway/time slotinterconnections are needed for each call. A first interconnection isneeded to transfer audio signals from the caller's DID card 42 to theswitch card 58, and a second interconnection is needed to transfer thosesignals to the subscriber's DID card. A third interconnection is neededto transfer audio signals originated from the subscriber's DID card 42to the switch card 58, and a fourth interconnection is needed totransfer those signals to the caller's DID card. These interconnectionsare established even in the event the caller's call and the subscriber'scall are received over the same DID card 42. After these resources areallocated, their identity is stored in the resource allocation field 124for the trunk pair record 121 for the call.

Simultaneously with the resource allocation step 218 (though depicted asoccurring sequentially thereafter), a call announcement step 220 isexecuted to inform the subscriber of the waiting call because there maybe instances when a subscriber calls his private number for reasonsunrelated to the outstanding page-connect page and does not know thatthere is a call waiting. After the announcement step 221, the mink task104 waits for the subscriber to enter a code indicating that he is notinterested in accepting the page-connect call as represented by step222. If the subscriber is not interested in accepting the page-connectcall, the mink task 104 allows the subscriber to use the other systemservices, as represented., by the alternative-services step 223. Thesystem also stops executing the page-connect task 126 for the callingparty. This is performed by an immediate branching to the sign-offsequence starting with the page count-decrement step 202. Also, as partof the alternative services step 223, the caller is informed that thesubscriber is unavailable and is then invited to a leave a voice mailmessage for the subscriber.

If the subscriber elects to proceed with the page-connect call, thetrunk task 104 directs the CPT card 47 to generate a short audio signalthat is played to the system subscriber as represented by generateconnect-tone step 225. Generate connect-tone step 226 is performed sothat the telephone call will occur much like a conventional or "plainold telephone service" call, wherein once the caller rings thesubscriber, the next thing that happens is that the called party picksup the telephone and is given the opportunity to respond by saying"hello" or other suitable greeting. Simultaneously with, or immediatelyafter execution of generate connect-tone step 225, a PCM highway connectstep 226 is performed. In PCM highway connect step 226, a fully duplexedlink between the caller and the subscriber is established by the systemover the PCM highway 64 using the individual highways and time slotsspecified in the resource allocation fields 124. At this stage, theparties are able to converse in a normal manner.

As the call progresses, the trunk task 104 monitors the length of thecall as represented by call determination step 228. If the call exceedsa predetermined amount of time, the following steps are performed toprevent page-connect calls from taking up so much time that it affectsthe system's ability to handle other pages. If after a predeterminedamount of time the parties have not disconnected, the trunk task 104will generate a warning tone, as represented by step 230, that will beaudible to both the subscriber and caller. The generation of this toneserves as an indication that the parties must terminate their callwithin a given period of time. If, at the end of this time, the partieshave not terminated the call, the trunk task 104 performs autodisconnectstep 232. In the autodisconnect step 232, the caller and subscriber areautomatically disconnected. Depending on its particular arrangement, thepaging system may generate an announcement just prior to the disconnectstep indicating that such step is being taken.

Once the caller and the subscriber have disconnected either voluntarily,as represented by step 233, or after the system performs theautodisconnect step 232, the system performs a page-connect pagecount-decrement step 234, wherein the page-connect page count field isdecremented. The system also performs trunk-pair-record erase step 236wherein the trunk pair record 121 in the trunk pair table 119 for thecall is erased.

The telecommunications system of this invention offers a convenientmeans to provide subscribers an economical interconnect service whereinthey can be readily connected to callers who are trying to reach them.This system, since it includes a paging system, can be offered as anadd-on service to the population that subscribes to the underlyingpaging service. There is no requirement that a paging system subscriberelect to use this page-connect service; the subscriber can elect to usethe service at his/her option. This allows a paging system subscriber toalways have some sort of a basic paging and/or voice-mail service and totake advantage of the page-connect paging service only when he/she has aparticular need for the service.

The prioritization subtask 132 of this paging system serves to placepaging requests for the page-connect pages at the head of the pagingrequest list 129. This ensures that these pages are generated andbroadcast first. This serves to minimize the amount of time that callersto page-connect subscribers have to wait for the subscribers to receivethe page and establish connection with the paging terminal 28 so thatthe call can be connected. This reduces the likelihood that a callerwill become impatient and hang up. Moreover, by reducing the time that acaller for a page-connect page subscriber is parked, the overall amountof time that is spent servicing page-connect calls, at the expense ofother system services, is similarly reduced.

Still another feature of this invention is that the execution of thepage-connect pages maximum-number-reached determination step 164 and ofthe page-connect call maximum-time-reached determination step 228 servesto minimize the extent to which page-connect pages monopolize the trunks66 connected to the paging terminal 28. This serves to minimize theextent to which page-connect pages may prevent other pages from beingprocessed by the terminal 28 and broadcast over the paging system.

The system subscribers of the telecommunications system of thisinvention who are also CT-2 system subscribers are provided with aconvenient means of using their CT-2 telephones to establish acommunications link whereby they not only can call other parties, butcan also be called themselves. Calls to system subscribers are simplybroadcast over the paging system. This eliminates the need to provideexpensive tracking circuitry with the CT-2 system so that the calls canbe routed to the subscribers over nearby base stations 36. Moreover, inthe event that the CT-2 subscriber is out of range of the base stations36, the system still offers subscribers significant utility. Thesubscriber will, over the pager 27, still be able to receive apage-connect page. Then, if the subscriber has ready access to someother telephone, he can complete the call though access to the PSTN 32even though the call cannot be completed through his handset 26.

FIG. 11 illustrates an alternative embodiment of a telecommunicationssystem 240 of this invention. In this embodiment of the invention, thereare two separate physical units, a page-connect connect unit 242 and apaging terminal 244. The paging terminal 244 has the base structuresimilar to that of the paging terminal 28 described with respect to thefirst embodiment of the invention. The page-connect connect unit 242includes one or more DID cards 42a, a VSB 46a, a CPT card 47a, a switchcard 58a, a DCC 52a, a BMIC 62a, a DMA bus 60a, and a hard drive 50athat are similar to the previously described paging terminal subunits.Digitized voice information is exchanged between the DID cards 42a, theVSB 46a, and the CPT card 47 over a PCM highway 64a. A switch card 58acontrols the exchange of information over the PCM highway 65. A CPU 48ain the page-connect connect unit 242 regulates the response of the unitto incoming calls. Data, control, and audio signals between thepage-connect page connect unit CPU 48a and the complementary CPU in thepaging terminal 244 are exchanged over a RS-232 serial data bus 246. Thesystem of this embodiment of the invention may further includecomplementary communications processes in the CPUs 48 and 48a tofacilitate the exchange of signals over bus 246.

In this embodiment of the invention, the lines connected to the pagingterminal 244 are public and private lines for subscribers who do notsubscribe to the page-connect paging service. The public and privatelines for the subscribers who take advantage of the page-connect pagingservice are all connected to the DID cards 42a in the page-connectconnect unit 242. When a call for a page-connect subscriber is receivedover one of the DID cards 42a in the page-connect connect unit 242, theCPU 48a processes the call in a similar manner to that described withrespect to the first described embodiment of the invention. Once the CPU48a generates a page request, the request is then forwarded over theRS-232 bus 246 to the CPU 48 in the paging terminal 244. Upon receipt ofthe paging request by the paging terminal CPU 48, the paging terminal244 then forms a page in the described manner and transmits it to thepaging stations 30 for subsequent broadcast. A subscriber's response tothe page-connect page is received over one of the page-connect connectunit DID cards 42a. When the response is received, the page-connectconnect unit CPU 48a then directs the switch card 58a to establish anappropriate connection between the DID cards 42a over the PCM highway64a so the connection between the caller and subscriber can beestablished. If the caller cannot be connected to the subscriber or ifthe call is from a subscriber for purposes other than establishing apage-connect call, the connect unit 242 serves as a voice mailbox inwhich the caller can leave a message that the subscriber can retrieve athis convenience.

As depicted by FIG. 12, this version of the invention can be configuredso that multiple page-connect connect units 242 can be connected to asingle paging terminal 244. Each page-connect connect unit 242 createspage requests in response to incoming calls for subscribers assigned tothe particular unit. The page requests are forwarded from thepage-connect connect units 242 to the paging terminal 244 over a set ofcommunication buses 246. The paging terminal 244, in response toreceiving a page request from one of the page-connect connect units 242,generates a page and forwards it to the paging stations 30 over theassociated bus 246 for broadcast. The subscriber can then establish aninterconnection with the caller by accessing the page-connect connectunit 242 that was accessed by the caller. In these versions of theinvention, the page-connect connect units 242 may be located in closeproximity with the paging terminal, i.e., the same room. When the systemis so constructed, communication bus 246 may take the form of an RS-232bus. Alternatively, one or more of the page-connect connect traits 242may be located several kilometer or more from the paging terminal. Inthis situation, communication bus 246 may take the form of a dedicatedfiber-optic link or a common carrier circuit. It may also be desirableto connect the page-connect connect units 242 to multiple pagingterminals 244. In the event one paging terminal 244 fails, the otherterminal would still be able to generate pages for forwarding to thesubscribers.

An advantage of this embodiment of the invention is that it provides ameans for system operators to first provide a paging service and then ata later time provide a page-connect paging service. Moreover, thisembodiment of the invention allows the system operators to configuretheir systems so that the page-connect subscribers' calls are allprocessed by one or more page-correct connect units 242 and the callsfor the other subscribers are processed by the regular paging terminal244. The PCM highway 64 (FIG. 11) in the paging terminal 244 forms thecommunication link over which voice messages are transferred to and fromnon-page-connect system subscribers. A second set of PCM highways, thePCM highways 64a (FIG. 11) in the page-connect connect traits 242function as the fully duplexed communications links used by page-connectsystem subscribers. This arrangement maximizes the number ofpage-connect subscribers the system can handle. Also, as the demand forpage-connect paging grows, the system can be reconfigured to accommodatethe additional subscribers through the installation of additionalpage-connect connect units 242. Still another advantage of thisarrangement is that a first set of P.S.T.N. trunk lines, trunk lines 66,can be dedicated to system subscribers that only want to use the basicpaging service while a second set of trunk lines, trunk lines 66a, canbe dedicated to the customers that want the page-connect paging service.

Furthermore, this embodiment of the invention allows an organization,such as a business or a hospital, to operate its own page-connect pagingsystem in conjunction with the paging network run by a largerorganization, such as a public utility. The organization that wants toprovide its members with page-connect paging would operate thepage-connect connect unit 242. The paging terminal 244 would be part ofa paging system operated by the public utility. The page requestsgenerated in response to incoming calls by the page-connect connect unit242 would be transmitted over any communication bus 246 to the pagingterminal 244. This arrangement offers a means for an organization tooffer its members a page-connect paging service without having to go tothe expense of operating its own paging stations 30 and supportequipment.

Moreover, still other versions of the invention may include the calleroption task 125, the call notifier task 139, or the subscriber optiontask 133 (FIG. 6). The caller option task 125 allows a person calling asubscriber to elect to have a page-connect page sent in order to try tobe connected to the subscriber or to have the call sent to analternative destination. As depicted by FIG. 13, if the system includesthis feature, once an incoming call is recognized as being directed to aparticular subscriber, the trunk task 104 first determines if thesubscriber is a page-connect subscriber who also subscribes to thecaller option package, as represented by step 252. If the subscriberdoes not employ these services, the trunk task proceeds to the otherservices step 155. In this version of the invention, the other servicesmay include the generation of a page-connect page according to thepreviously described process. If the subscriber employs the calleroption task 125, the task 125 is executed. The caller option task 125initially performs an announce options step 254. In step 254, the systeminvites the caller to wait to be connected to the subscriber, leave amessage in the subscriber's voice mailbox, or be connected to someoneelse, for example, the subscriber's secretary. This message is in theform of a standard message that is the same regardless of the subscriberto whom the incoming call is directed or it may be a customized messagethat was prerecorded by the system subscriber. The caller then overdialsa command to the system to indicate the selected option as representedby step 255. Based on that command entered by the caller, the systemtakes appropriate action as represented by step 257. These actionsinclude executing the page-connect task 126, connecting to thesubscriber's voice mailbox, or forwarding the call to the designatedtelephone.

The call notifier task 139 (FIG. 6) is used by a subscriber who may wantto have a page forwarded to a specific telephone number based on thetime of day the call is received. For example, an individual may want apage sent to a private business phone during the business day, a carphone or a pager during evening commuting hours, a home phone in theevening, and a voice mailbox on the weekends. The call notifier task 139maintains an outcall code table 260, depicted by FIG. 14, and a timetable 262, depicted by FIG. 15 for each subscriber who uses the task.The outcall code table contains a set of subscriber-generated outcallcode fields (OCFs) 261 that designate the numbers to which thesubscriber wants the page forwarded. Each outcall code field 261comprises either a telephone number where the subscriber wants the callforwarded or the cap code of a pager to which the call should beforwarded. In versions of the invention that have this feature, the capcode field 116 in the record 108 (FIG. 7) of a subscriber who employsthis feature will actually contain an address that points to the timetable 262 for the subscriber. The time table 262 contains a set ofuser-generated time block fields (TBFs) 266. Each time block field 266contains a pointer to the outcall code field 261 that contains theindication of which number a page should be forwarded based on theday-of-week and time-of-day it is received.

Whenever a page, such as page-connect page, is generated, based on thematerial contained in the cap code field 116 for the subscriber, thequeuing and coding task 128 will either generate a page for broadcast tothe single pager assigned to the subscriber or execute the call notifiertask 139 (FIG. 6). The call notifier task 139, based on the currentday-of-week and time-of-day and the data in the time table 262 for thesubscriber, determines which outcall code field 261 (FIG. 14) containsan indication of the telephone number or pager to which the page shouldbe forwarded. If the designated outcall code field 261 contains a capcode indicating the page should be forwarded to a pager, the queuing andcoding task 128 generates the page in the normal manner and the page isforwarded to the paging stations 30 (FIG. 1) through a UOE card 44 (FIG.2). If the designated outcall code field 261 contains an indication thatthe page is to be forwarded to a conventional telephone, the queuing andcoding task 128 forwards the page to a DID card 42 (FIG. 2). Based oncoding signals placed in the page by the queuing and coding task 128,the signal generator on the DID card 42 places a call to the designatedtelephone over a free trunk line. The call contains a message generatedby the queuing and coding task that informs the subscriber of the page.

The subscriber option task 133 (FIG. 6) gives the subscriber a number ofoptions on how to respond to a page-connect page. In versions of theinvention in which this task 133 is installed, the trunk task 104 firstdetermines if the subscriber employs this feature as represented by step270 in FIG. 16. If the subscriber does not employ this feature, thesystem proceeds to the alternative services step 155. Step 155 may, insome versions of the invention, include the initiation of the previouslydescribed page-connect process. If the subscriber employs this feature,the system invites the caller to identify himself as depicted by calleridentification step 272. In caller identification step 272, the callerspeaks his name in response to a voice prompt from the system or mayoverdial a set of digits to provide an alternative form ofidentification. When the invention is installed into a PSTN 32 thatoffers automatic number identification, the PSTN will automaticallyprovide an indication of the telephone number from which the call wasmade. In these versions of the invention, it may be possible toeliminate the caller identification step 272.

The processing of the page-connect call then proceeds in the normalmanner. As part of the generate page-connect step 178, an indication ofthe calling part 3, is embedded in the page. If the subscriber has avoice pager 29 or the call notifier is employed to forward the page to atelephone, the caller's spoken identification will be forwarded to thesubscriber as represented by step 275. If a series of digits wereentered to identify the caller, the digits may be presented on a displayintegral with the pager or spoken to the subscriber after beinggenerated by a speech synthesis module. If the page was simply beingsent to a subscriber with a tone-only pager, the system informs thesubscriber of the identity of the caller when the subscriber calls thesystem.

Once the subscriber is informed of the identity of the caller, thesubscriber performs a page-connect option step 276. In this step, thesubscriber enters an overdial command that indicates his willingness toproceed with the page-connect call and speak with the caller, forwardthe call to an alternative destination or to have the call disconnected.Depending on how the system is configured, the subscriber can forwardthe call to a specific telephone number, for example, a secretarialstation, or to the subscriber's voice mailbox so the caller can leave amessage.

The caller option task 125 provides the caller with the option of eitherhaving the page-connect task 126 executed, so that the caller can try tobe connected to the subscriber, or to simply leave a message in thesubscriber's voice-mailbox. Thus, in the event the caller does not needto speak with the subscriber, the caller can simply leave a message andis free from having to wait for the system to execute the wholepage-connect process. The call notifier task 139 forwards pages,including page-connect pages, to the pager or the terminal deviceclosest to the subscriber depending on the day-of-week and thetime-of-day. This maximizes the possibility that the page will beforwarded to a terminal near the subscriber so that the subscriber willrespond to the call. The subscriber option task 133 allows thesubscriber to determine who is calling and whether or not thepage-connect call should be completed or routed to an alternativedestination.

The foregoing description has been limited to specific embodiments ofthe invention. It will be apparent, however, that variations andmodifications may be made to the invention with the attainment of someor all of the advantages of the invention. For example, the describedhardware components of this invention are illustrative and are not to beconstrued as limiting. For instance, the DID cards 42 described asperforming the interface functions can be readily replaced by otherinterface boards, such as end-to-end cards. Incorporation of these cardswould require a caller to overdial a set of digits into the system toprovide a header message for the CPU 48 to indicate whether the callerwas a subscriber, or merely a person trying to reach the subscriber, andthe particular identity of the relevant subscriber. Other versions ofthe invention may employ digital trunk cards (DSIs) as the interfaceboards. Also, in some versions of the invention there may be more thanone hard drive 50. In these versions of the invention, multiple harddrives may be connected to a single DCC 52 through a common bus. Itshould further be understood that in these versions, while each harddrive 50 is a separate physical unit, collectively they functiontogether as a single, common, memory for storing voice messages andpages that are received over any of the DID cards 42. In a similar vein,it should be understood that there may be more than one microprocessor92 in the central processing unit 48. In these versions of theinvention, one microprocessor may, for example, handle the mink tasks104 while the other microprocessor may execute the Q & C tasks 128, theUOE task 134, and the voice storage task 136. Furthermore, it should beclear that in some versions of the invention the UOE cards 44 mayactually form the page batches 68 and send them prior to theirtransmission to the paging transmitters, as opposed to having thebatches formed by a task running on the CPU 48. It should similarly beunderstood that this system need not employ the CT-2 equipment describedin this application. The telecommunications system of this invention mayemploy any telephone equipment that allows a subscriber to make a callthrough the PSTN. The advantage of this 'system is that it eliminatesthe need to provide tracking equipment that is otherwise needed toinform a subscriber that he/she has an incoming call. The features oroptions the system of this invention offers a subscriber may also varywith the services offered by the utility that operates the publiclyswitched telephone network 32 to which the system is connected.

It should also be recognized that in some versions of the invention itmay be possible to eliminate the switch card 58 and/or the call progresstone card 47. The switch card 58 could be eliminated by providing asignal bus that does not have dedicated transmit and receive highwaysand by giving the central processing unit that controls overalloperation of the paging terminal 28 the ability to establish inter-cardsignal transfer over the bus. The call progress tone card 47 can beeliminated by providing the terminal with one or more digital signalprocessors that are capable of generating the digital-signal versions ofthe various tones callers to the system should hear. The digital signalprocessors can also be used to generate the DTMF switch code tones thatare produced when the system makes an outcall during the execution ofthe call notifier task 139. Furthermore, in some systems it should berecognized that the digitized signal transfer of voice signals betweenthe cards may not be in PCM format but in other digital signal formats,for example, adaptive differential pulse code modulation, ADPCM format.

It should similarly be understood that there is no requirement that eachpage-connect subscriber be provided with both a public telephone numberand a private telephone number. In some versions of the invention thesubscriber may have just a single telephone number that he/she candistribute. When a person accessing the subscriber uses the number, thecall will be processed in a manner similar to that described above. Whenthe subscriber accesses the system, he/she will use the same number andoverdial an identification code into the system to serve as a messagethat the call is from the subscriber. The call will then be processedlike a call over the subscriber's private number. In these embodimentsof the invention, the trunk pair table 119 for each page-connect eachcontains a single subscriber number field to indicate that it isprocessing a call for that subscriber, a first mink identification fieldto identify the location of the caller's call on a DID card, and asecond mink identification field to identify the subscriber's call.

Moreover, it is clear that there are numerous variations in how thesystem may operate. For example, some particular subscribers may electto be page-connect page subscribers but not voice-mail subscribers.Callers who are not connected to the called subscribers would not beinvited to leave messages for later retrieval. Some versions of theinvention may alternatively be arranged so that the subscriber mustfirst enter an accept code to indicate he wants to accept a page-connectcall as opposed to entering a code only when he is not willing to accepta page-connect call. It should further be understood that, in someenhanced versions of the system, it may be desirable to provide operatorassistance in the event the caller needs help using the system or asubscriber needs the same type of assistance. It should further beunderstood that the described software tasks and steps performed therebyare similarly meant to be exemplary. For example, in some versions ofthe invention the queuing and coding tasks and the UOE tasks may beperformed by a single monolithic software module. Also the page-connecttask 126 may not be a distinct subtask of the trunk task 104. Instead,the page-connect task 126 may be a collection of smaller tasks that arecontained within the trunk task 104 and arranged to cooperate so thatthe pagerconnect call connections are established. In a similar vein, itshould be understood that the page connect task 126, the caller optiontask 125, and the call notifier task 139 may not be distinct tasks butmaybe integrated into other software processes.

Furthermore, the steps performed may vary either in the order in whichthey are performed or in their nature. For instance, in some versions ofthe system, it may not be necessary to perform the page-connect pagemaximum-number-determination step 164 or the page-connectcall-time-limiting step 222 to limit the number of page-connect calls.Furthermore, some subscribers may be provided with a page-until-pickupfeature. In this feature, the subscriber is repetitively paged until hecalls the paging terminal 28 or the caller hangs up. While not arecommended feature to be employed with the page-connect system of thisinvention, it is one that could be employed if it was necessary forparticular subscribers. Thus, it is the object of the appended claims tocover all such variations and modifications as come within the truespirit and scope of this invention.

While the preferred embodiment of the invention has been illustrated anddescribed, it will be appreciated that various changes can be madetherein without departing from the spirit and scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A telecommunicationssystem capable of receiving telephone calls for meet-me page subscribersand telephone calls for non-meet-me page subscribers from a publiclyswitched telephone network, wherein the subscribers are provided withportable page receivers, comprising:a paging system including a firstprocessing circuit connected to the publicly switched telephone networkfor receiving telephone calls to the non-meet-me page subscribers,which, in response to the telephone calls, generates page requests; asecond processing circuit connected to said first processing circuit forreceiving said page requests, which, in response to said page requests,forms one of pages or page messages according to a time of the day atwhich the page requests are received and selectively forwards said oneof pages or page messages to one of a plurality of terminal devices; ameet-me unit connected to the publicly switched telephone network forreceiving telephone calls to the meet-me page subscribers and forreceiving telephone calls from the meet me page subscribers, whereinsaid meet-me unit is capable of distinguishing between calls to themeet-me page subscribers and calls from the meet-me page subscribers andin response to an incoming call for a specific meet-me page subscriber,generates a meet-me page request and parks the incoming call, saidmeet-me unit including means for generating a ring signal to a callerfor a predefined time interval while said incoming call is parked, sothat a caller is at least initially unaware that a meet-me page requesthas been generated and wherein said meet-me unit is further connected tosaid paging systems second processing circuit for forwarding saidmeet-me page request thereto; and call connection circuitry integralwith said meet-me unit for determining from which meet-me pagesubscriber that said meet-me page subscriber call has been received,determining if said parked call is for the calling meet-me pagesubscriber; and, if said parked call is for the calling meet-me pagesubscriber, establishing a single link between said parked call and thecall from the meet-me page subscriber, said caller being connected incommunication with the calling meet-me page subscriber without beinginformed that the calling meet-me page subscriber has been paged if thesignal link is established within said predefined time interval.
 2. Thetelecommunications system of claim 1, wherein a terminal device is apaging station connected to said second processing circuit for receivingsaid pages and broadcasting said pages to the paging receivers.
 3. Thepaging terminal of claim 1, wherein:said first processing circuit isfurther configured to obtain a caller identification if the call is to ameet-me system subscriber and forward the caller identification to saidsecond processing circuit; said second processing circuit generates saidpages so that said page forwarded to the meet-me system subscriberincludes the caller identification; and said first processing circuit isfurther configured to receive a command entered by the meet-me pagesystem subscriber and selectively connects the caller to the meet-mepage system subscriber based on the command entered by the meet-me pagesystem subscriber.
 4. The paging terminal of claim 1 or 3, wherein saidfirst processing circuit is configured to receive a command from thecaller to the meet-me page system subscriber and, based on the receivedcommand, generates said page request to said second processing circuitor connects the caller to an alternative service.
 5. The paging terminalof claim 4, wherein said second processing circuit selectively forwardssaid page to a page receiver or to a terminal device accessed throughthe publicly switched telephone network based on when the call to thepage-connect page system subscriber is received.
 6. The paging terminalof claim 4, wherein said plurality of terminal devices are accessedthrough the publicly switched telephone network.
 7. A meet-me unitconnected to a publicly switched telephone network for receivingtelephone calls to meet-me page subscribers and for receiving telephonecalls from the meet-me page subscribers, and further connected to apaging terminal, said unit comprising:a first processing unit capable ofdistinguishing between calls to the meet-me page subscribers and callsfrom the meet-me page subscribers and in response to an incoming callfor a specific meet-me page subscriber, generating a meet-me pagerequest, selectively forwarding said page request to one of a pluralityof terminal devices based on a time of day at which the call to thesystem subscriber is received, and parking the incoming call; and asecond processing unit connected to said first processing unit fordetermining from which a meet-me page subscriber a call is received,determining if said parked call is for the meet-me page subscriberunless a predefined number of incoming lines are busy, where saidpredefined number is substantially less than a maximum available of thenumber of incoming lines; and if said parked call is for the meet-mepage subscriber who is calling, establishing a single link between saidparked call and the call from the meet-me page system subscriber who iscalling.
 8. The meet-me unit of claim 7 wherein one of a plurality ofterminal devices is the paging terminal.